Freudian Unconscious and Cognitive Neuroscience

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'... [T]he psychological unconscious documented by latter-day scientific psychology is quite different from what Sigmund Freud and his psychoanalytic colleagues had in mind in fin de siecle Vienna. Their unconscious was hot and wet; it seethed with lust and anger; it was hallucinatory, primitive, and irrational. The unconscious of contemporary psychology is kinder and gentler than that and more reality bound and rational, even if it is entirely cold and dry.'

It was this 'hot and wet' perception of Freud's notion of the unconscious that first attracted me to psychoanalysis. However, the question regarding whether, when neuroscientists speak of unconscious processing, they are speaking in the same terms as psychoanalysts or not, has become of increasing interest to me. It was, therefore, my sense that Talvitie's work served as something of a bridge between the two paradigms that drew me to it.

As is the case with all mental phenomena, the questions about just how and where the unconscious might be are associated with the mind-body problem that distinguishes monists and dualists. For monists, mind emerges from brain activity. Dualists hold that mind and brain are separate and cannot be reduced to each other. Dualism has largely fallen out of favour with most neuroscientists, and Talvitie (2) himself is clearly a monist. At the same time, while there is consensus that mind or consciousness emerges from neurophysiological processes, there remains a lack of clarity as to how this is achieved. Talvitie (p. 50) (2) goes as far as to make the point that cognitive science has little doubt that unconscious matters determine our behaviour. Rather, it is the role and emergence of consciousness that is in question.

At the same time, the two are clearly related. It would seem that consciousness is a limited product of the functioning of the mind. We know we can hold only seven units of information in working memory, and most people are able to retain only four units of visuospatial information. What happens to other information? Is there other information? If there is, is it processed unconsciously?

These questions have been asked for a long time now, and various routes have been utilised by neuroscientists in their quest to answer them. Benjamin Libet (Talvitie, (2) p. 50) has shown that readiness potential occurs 220 - 550 milliseconds before the conscious decision to move one's finger. In addition to subliminal priming, split-brain studies have been used to show that subjects presented with sensory input to one hemisphere do not perceive this input from the other hemisphere. Another route has related to analyses of memory processes. We know that explicit or declarative memory, which is the memory for facts and events, depends on the hippocampus and is stored in a distributed network throughout the brain. Implicit or procedural memory, on the other hand, is the learning of various skills and relies on changes to the domain-specific neural processors involved in that skill, so that, for example, motor regions will be involved in the learning of a finger sequencing task. Amnesics exhibiting a deficit in explicit memory continue to retain their ability to learn new skills and habits, so that although they may not recall the learning event, their performance is influenced by this experience.

The psychoanalytic idea that a memory may be stored in the unconscious, only to emerge intact at a later stage, has however been challenged by neuroscience. Cognitive neuroscience has revealed that our memory processes are highly subject to error. As we grow older, source memory or our memory of the context in which an event took place begins to fail. As Martha Weinman Lear (p. 106) (3) explains, various emotions such as guilt or desire, associated with a particular memory, may affect our recollection of it. …